Re: [boost] [Block Pointer] benchmark

Subject: Re: [boost] [Block Pointer] benchmark
From: Phil Bouchard (philippe_at_[hidden])
Date: 2011-05-26 19:42:04

On 5/26/2011 4:19 PM, Phil Bouchard wrote:
>
> I'm not sure what it is deleting.

If I examine worker_make used with block_ptr it's obvious it creates 
temporaries all over the place and there is no such RVO:

push   %r15
xor    %r15d,%r15d
push   %r14
push   %r13
push   %r12
push   %rbp
push   %rbx
sub    $0x48,%rsp
lea    0x10(%rsp),%rax
mov    %rax,%rdi
mov    %rax,0x8(%rsp)
callq  0x408a30 <block_ptr>
lea    0x20(%rsp),%rax
mov    %rax,(%rsp)
mov    %rax,%rdi
nop
callq  0x4094f0 <boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>()>
callq  0x407c60 <boost::detail::bp::block_header::static_mutex()>
mov    %rax,%rdi
mov    %rax,%r14
callq  0x405258 <pthread_mutex_lock_at_plt>
test   %eax,%eax
jne    0x409d34 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+804>
mov    0x18(%rsp),%rdx
mov    0x8(%rdx),%rcx
mov    0x8(%rcx),%rax
cmp    %rax,%rcx
jne    0x409a74 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+100>
jmp    0x409a81 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+113>
mov    %rcx,%rax
mov    %rax,0x8(%rdx)
mov    0x8(%rax),%rcx
cmp    %rax,%rcx
jne    0x409a71 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+97>
mov    0x28(%rsp),%rsi
mov    0x8(%rsi),%rdx
mov    0x8(%rdx),%rax
cmp    %rax,%rdx
jne    0x409a98 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+136>
jmp    0x409aa5 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+149>
mov    %rdx,%rax
mov    %rax,0x8(%rsi)
mov    0x8(%rax),%rdx
cmp    %rax,%rdx
jne    0x409a95 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+133>
cmp    %rdx,%rcx
je     0x409ba9 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+409>
xor    %esi,%esi
mov    0x8(%rsp),%rdi
callq  0x408500 <boost::detail::bp::block_ptr<int>::release(bool)>
mov    0x28(%rsp),%rcx
mov    0x8(%rcx),%rdx
mov    0x8(%rdx),%rax
cmp    %rax,%rdx
jne    0x409ad3 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+195>
jmp    0x409ae0 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+208>
xchg   %ax,%ax
mov    %rdx,%rax
mov    %rax,0x8(%rcx)
mov    0x8(%rax),%rdx
cmp    %rax,%rdx
jne    0x409ad0 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+192>
mov    0x18(%rsp),%rcx
mov    0x8(%rcx),%rsi
mov    0x8(%rsi),%rax
cmp    %rax,%rsi
jne    0x409af7 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+231>
jmp    0x409b04 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+244>
mov    %rsi,%rax
mov    %rax,0x8(%rcx)
mov    0x8(%rax),%rsi
cmp    %rax,%rsi
jne    0x409af4 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+228>
cmp    %rsi,%rdx
je     0x409ba9 <void worker_make<boost::detail::bp::block_ptr<int>, 
&(boost::detail::bp::block_ptr<int> 
boost::detail::bp::make_block<int>())>()+409>
lea    0x28(%rsi),%r8
...

-Phil